The invention relates to pyrimidine derivatives, or pharmaceutically-acceptable salts or in-vivo-hydrolysable esters thereof, which possess anti-cell proliferative (such as anti-cancer) activity and are therefore useful in methods of treatment of the human or animal body. The invention also relates to processes for the manufacture of said pyrimidine derivatives, to pharmaceutical compositions containing them and to their use in the manufacture of medicaments for use in the production of an anti-cell proliferation (anti-cancer) effect in a warm-blooded animal such as man.
A family of intracellular proteins called cyclins play a central role in the cell cycle. The synthesis and degradation of cyclins is tightly controlled such that their level of expression fluctuates during the cell cycle. Cyclins bind to cyclin-dependent serine/threonine kinases (CDKs) and this association is essential for CDK (such as CDK1, CDK2, CDK4 and/or CDK6) activity within the cell. Although the precise details of how each of these factors combine to regulate CDK activity is poorly understood, the balance between the two dictates whether or not the cell will progress through the cell cycle.
The recent convergence of oncogene and tumour suppressor gene research has identified regulation of entry into the cell cycle as a key control point of mitogenesis in tumours. Moreover, CDKs appear to be downstream of a number of oncogene signalling pathways. Disregulation of CDK activity by upregulation of cyclins and/or deletion of endogenous inhibitors appears to be an important axis between mitogenic signalling pathways and proliferation of tumour cells.
Accordingly it has been recognised that an inhibitor of cell cycle kinases, particularly inhibitors of CDK2, CDK4 and/or CDK6 (which operate at the S-phase, G1-S and G1-S phase respectively) should be of value as a selective inhibitor of cell proliferation, such as growth of mammalian cancer cells.
The present invention is based on the discovery that certain 4,6-pyrimidine compounds surprisingly inhibit the effects of cell cycle kinases showing selectivity for CDK2, CDK4 and CDK6, and thus possess anti-cancer (anti-cell proliferation) properties. Such properties are expected to be of value in the treatment of disease states associated with aberrant cell cycles and cell proliferation such as cancers (solid tumours and leukemias), fibroproliferative and differentiative disorders, psoriasis, rheumatoid arthritis, Kaposi""s sarcoma, haemangioma, acute and chronic nephropathies, atheroma, atherosclerosis, arterial restenosis, autoimmune diseases, acute and chronic inflammation, bone diseases and ocular diseases with retinal vessel proliferation.
According to the invention there is provided a pyrimidine derivative of the formula (I) 
wherein
R1 is selected from (1-6C)alkyl [optionally substituted by one or two substituents independently selected from halo, amino, (1-4C)alkylamino, di-[(1-4C)alkyl]amino, hydroxy, cyano, (1-4C)alkoxy, (1-4C)alkoxycarbonyl, carbamoyl, xe2x80x94NHCO(1-4C)alkyl, trifluoromethyl, phenylthio, phenoxy, pyridyl, morpholino], benzyl, 2-phenylethyl, (3-5C)alkenyl [optionally substituted by up to three halo substituents, or by one trifluoromethyl substituent, or one phenyl substituent], N-phthalimido-(1-4C)alkyl, (3-5C)alkynyl [optionally substituted by one phenyl substituent] and (3-6C)cycloalkyl-(1-6C)alkyl;
wherein any phenyl or benzyl group in R1 is optionally substituted by up to three substituents independently selected from halogeno, hydroxy, nitro, amino, (1-3C)alkylamino, di-[(1-3C)alkyl]amino, cyano, trifluoromethyl, (1-3C)alkyl [optionally substituted by 1 or 2 substituents independently selected from halogeno, cyano, amino, (1-3C)alkylamino, di-[(1-3C)alkyl]amino, hydroxy and trifluoromethyl], (3-5C)alkenyl [optionally substituted by up to three halo substituents, or by one trifluoromethyl substituent], (3-5C)alkynyl, (1-3C)alkoxy, xe2x80x94SH, xe2x80x94S-(1-3 C)alkyl, carboxy, (1-3 C)alkoxycarbonyl;
Q1 and Q2 are independently selected from phenyl, naphthyl, indanyl and 1,2,3,4-tetrahydronaphthyl;
and one or both of Q1 and Q2 bears on any available carbon atom one substituent of the formula (Ia) and Q2 may optionally bear on any available carbon atom further substituents of the formula (Ia) 
xe2x80x83[provided that when present in Q1 the substituent of formula (Ia) is not adjacent to the xe2x80x94NHxe2x80x94 link];
wherein
X is CH2, O, S, NH or NRx [wherein Rx is (1-4C)alkyl, optionally substituted by one substituent selected from halo, amino, cyano, (1-4C)alkoxy or hydroxy];
Y is H or as defined for Z; Z is OH, SH, NH2, (1-4C)alkoxy, (1-4C)alkylthio, xe2x80x94NH(1-4C)alkyl, xe2x80x94N[(1-4C)alkyl]2, xe2x80x94NH-(3-8C)cycloalkyl, pyrrolidin-1-yl, piperidin-1-yl, piperazin-1-yl [optionally substituted in the 4-position by (1-4C)alkyl or (1-4C)alkanoyl], morpholino or thiomorpholino; n is 1, 2 or 3; m is 1, 2 or 3;
and Q1 and Q2 may each optionally and independently bear on any available carbon atom up to four substituents independently selected from halogeno, hydroxy, thio, nitro, carboxy, cyano, (2-4C)alkenyl [optionally substituted by up to three halo substituents, or by one trifluoromethyl substituent], (2-4C)alkynyl, (1-5C)alkanoyl, (1-4C)alkoxycarbonyl, (1-6C)alkyl, hydroxy-(1-6C)alkyl, fluoro-(1-4C)alkyl, amino-(1-3C)alkyl, (1-4C)alkylamino-(1-3C)alkyl, di-[(1-4C)alkyl]amino-(1-3C)alkyl, cyano-(1-4C)alkyl, (2-4C)alkanoyloxy-(1-4C)-alkyl, (1-4C)alkoxy-(1-3C)alkyl, carboxy-(1-4C)alkyl, (1-4C)alkoxycarbonyl-(1-4C)alkyl, carbamoyl-(1-4C)alkyl, N-(1-4C)alkylcarbamoyl-(1-4C)alkyl, N,N-di-[(1-4C)alkyl]-carbarmoyl-(1-4C)alkyl, pyrrolidin-1-yl-(1-3 C)alkyl, piperidin-1-yl-(1-3C)alkyl, piperazin-1-yl-(1-3C)alkyl, morpholino-(1-3 C)alkyl, thiomorpholino-(1-3C)alkyl, piperazin-1-yl, morpholino, thiomorpholino, (1-4C)alkoxy, cyano-(1-4C)alkoxy, carbamoyl-(1-4C)alkoxy, N-(1-4C)alkylcarbarnoyl-(1-4C)alkoxy, N,N-di-[(1-4C)alkyl]-carbarmoyl-(1-4C)alkoxy, 2-aminoethoxy, 2-(1-4C)alkylaminoethoxy, 2-di-[(1-4C)alkyl]aminoethoxy, (1-4C)alkoxycarbonyl-(1-4C)alkoxy, halogeno-(1-4C)alkoxy, 2-hydroxyethoxy, (2-4C)alkanoyloxy-(2-4C)alkoxy, 2-(1-4C)alkoxyethoxy, carboxy-(1-4C)alkoxy, (3-5C)alkenyloxy, (3-5C)alkynyloxy, (1-4C)alkylthio, (1-4C)alkylsulphinyl, (1-4C)alkylsulphonyl, hydroxy-(2-4C)alkylthio, hydroxy-(2-4C)alkylsulphinyl, hydroxy-(2-4C)alkylsulphonyl, ureido (H2Nxe2x80x94COxe2x80x94NHxe2x80x94), (1-4C)alkylNHxe2x80x94COxe2x80x94NHxe2x80x94, di-[(1-4C)alkyl]- Nxe2x80x94COxe2x80x94NHxe2x80x94, (1-4C)alkylNHxe2x80x94COxe2x80x94N[(1-4C)alkyl]- , di-[(1-4C)alkyl]Nxe2x80x94COxe2x80x94N[(1-4C)alkyl]-, carbamoyl, N-[(1-4C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, amino, (1-4C)alkylamino, di-[(1-4C)alkyl]amino, (2-4C)alkanoylamino,
and also independently, or where appropriate in addition to, the above optional substituents, Q1 and/or Q2 may optionally bear on any available carbon atom up to two further substituents independently selected from (3-8C)cycloalkyl, phenyl-(1-4C)alkyl, phenyl-(1-4C)alkoxy, phenylthio, phenyl, naphtnyl, benzoyl, phenoxy, benzimidazol-2-yl and a 5- or 6-membered aromatic heterocycle (linked via a ring carbon atom and containing one to three heteroatoms independently selected from oxygen, sulphur and nitrogen); wherein said naphthyl, phenyl, benzoyl, 5- or 6-membered aromatic heterocyclic substituents and the phenyl group in said phenyl-(1-4C)alkyl, phenylthio, phenoxy and phenyl-(1-4C)alkoxy substituents may optionally bear up to five substituents independently selected from halogeno, (1-4C)alkyl and (1-4C)alkoxy; or a pharmaceutically-acceptable salt or in-vivo-hydrolysable ester thereof.
A suitable value for a ring substituent when it is a 5- or 6-membered aromatic heterocycle (linked via a ring carbon atom and containing one to three heteroatoms independently selected from oxygen, sulphur and nitrogen) is, for example, pyrrole, furan, thiophene, imidazole, oxazole, isoxazole, thiazole, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl or p-isoxazine.
In this specification the term xe2x80x9calkylxe2x80x9d includes both straight and branched chain alkyl groups but references to individual alkyl groups such as xe2x80x9cpropylxe2x80x9d are specific for the straight chain version only. An analogous convention applies to other generic terms.
Suitable values for the generic radicals (such as in R1 and in substituents on Q1 and Q2) referred to above include those set out below:
when it is halogeno is, for example, fluoro, chloro, bromo and iodo; (2-4C)alkenyl is, for example, vinyl and allyl; when it is (3-5C)alkenyl is, for example, allyl or buten-3-yl; when it is (3-5C)alkynyl is, for example, propyn-2-yl; when it is (2-4C)alkynyl is, for example, ethynyl and propyn-2-yl; when it is (3-6C)cycloalkyl-(1-6C)alkyl is, for example, cyclopropylmethyl; when it is (3-8C)cycloalkyl is, for example, cyclobutyl, cyclopentyl or cyclohexyl; when it is (1-4C)alkanoyl or (1-5C)alkanoyl is, for example, formyl and acetyl;
when it is (1-4C)alkoxycarbonyl is, for example, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl and tert-butoxycarbonyl; when it is (1-3C)alkyl is, for example, methyl, ethyl, propyl, isopropyl; when it is (1-4C)alkyl is, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl or tert-butyl; when it is (1-6C)alkyl is, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl or 3-methylbutyl or hexyl; when it is hydroxy-(1-3C)alkyl is, for example, hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl and 3-hydroxypropyl; when it is hydroxy-(2-4C)alkyl is, for example, 2-hydroxyethyl and 3-hydroxypropyl; when it is fluoro-(1-4C)alkyl is, for example, fluoromethyl, difluoromethyl, trifluoromethyl and 2-fluoroethyl; when it is amino-(1-3C)alkyl is, for example, aminomethyl, 1-aminoethyl and 2-aminoethyl; when it is (1-4C)alkylamino-(1-3C)-alkyl is, for example, methylaminomethyl, ethylaminomethyl, 1-methylaminoethyl, 2-methylaminoethyl, 2-ethylamimoethyl and 3-methylaminopropyl; when it is di-[(1-4C)alkyl]amino-(1-3C)alkyl is, for example, dimethylaminomethyl, diethylaminomethyl, 1-dimethylaminoethyl, 2-dimethylaminomethyl and 3-dimethylaminopropyl; when it is cyano-(1-4C)alkyl is, for example cyanomethyl, 2-cyanoethyl and 3-cyanopropyl; when it is (2-4C)alkanoyloxy-(1-4C)-alkyl is, for example, acetoxymethyl, propionyloxymethyl, butyryloxymethyl, 2-acetoxyethyl and 3-acetoxypropyl; when it is (1-4C)alkoxy-(1-3C)alkyl is, for example, methoxymethyl, ethoxymethyl, 1-methoxyethyl, 2-methoxyethyl, 2-ethoxyethyl and 3-methoxypropyl; when it is carboxy-(1-4C)alkyl is, for example carboxymethyl, 1-carboxyethyl, 2-carboxyethyl and 3-carboxypropyl; when it is (1-4C)alkoxycarbonyl-(1-4C)alkyl is, for example, methoxycarbonylmethyl, ethoxycarbonylmethyl, tert-butoxycarbonylmethyl, 1-methoxycarbonylethyl, 1-ethoxycarbonylethyl, 2-methoxycarbonylethyl, 2-ethoxycarbonylethyl, 3-methoxycarbonylpropyl and 3-ethoxycarbonylpropyl; when it is carbamoyl-(1-4C)alkyl is, for example carbamoylmethyl, 1-carbamoylethyl, 2-carbamoylethyl and 3-carbamoylpropyl; when it is N-(1-4C)alkylcarbamoyl-(1-4C)alkyl is, for example, N-methylcarbamoylmethyl, N-ethylcarbamoylmethyl, N-propylcarbamoylmethyl, 1-(N-methylcarbamoyl)ethyl, 1-(N-ethylcarbamoyl)ethyl, 2-(N-methylcarbamoyl)ethyl, 2-(N-ethylcarbamoyl)ethyl and 3-(N-methylcarbamoyl)propyl;
when it is N,N-di-[(1-4C)alkyl]-carbamoyl-(1-4C)alkyl is, for example, N,N-dimethylcarbamoylmethyl, N-ethyl-N-methylcarbamoylmethyl, N,N-diethylcarbamoylmethyl, 1-(N-dimethylcarbamoyl)ethyl, 1-(N,N-diethylcarbamoyl)ethyl, 2-(N,N-dimethylcarbamoyl)ethyl, 2-(N,N-diethylcarbamoyl)ethyl and 3-(N,N-dimethylcarbamoyl)propyl; when it is pyrrolidin-1-yl-(1-3C)alkyl is, for example, pyrrolidin-1-ylmethyl and 2-pyrrolidin-1-ylethyl; when it is piperidin-1-yl-(1-3C)alkyl is, for example, piperidin-1-ylmethyl and 2-piperidin-1-ylethyl; when it is piperazin-1-yl-(1-3C)alkyl is, for example, piperazin-1-ylmethyl and 2-piperazin-1-ylethyl; when it is morpholino-(1-3C)alkyl is, for example, morpholinomethyl and 2-morpholinoethyl; when it is thiomorpholino-(1-3C)alkyl is, for example, thiomorpholinomethyl and 2-thiomorpholinoethyl; when it is (1-4C)alkoxy is, for example, methoxy, ethoxy, propoxy, isopropoxy or butoxy; when it is cyano-(1-4C)alkoxy is, for example, cyanomethoxy, 1-cyanoethoxy, 2-cyanoethoxy and 3-cyanopropoxy; when it is carbamoyl-(1-4C)alkoxy is, for example, carbamoylmethoxy, 1-carbamoylethoxy, 2-carbamoylethoxy and 3-carbamoylpropoxy; when it is N-(1-4C)alkylcarbamoyl-(1-4C)alkoxy is, for example, N-methylcarbamoylmethoxy, N-ethylcarbamoylmethoxy, 2-(N-methylcarbamoyl)ethoxy, 2-(N-ethylcarbamoyl)ethoxy and 3-(N-methylcarbarmoyl)propoxy; when it is N,N-di-[(1-4C)alkyl]-carbamoyl-(1-4C)alkoxy is, for example, N,N-dimethylcarbamoylmethoxy, N-ethyl-N-methylcarbamoylmethoxy, N,N-diethylcarbamoylmethoxy, 2-(N,N-dimethylcarbamoyl)ethoxy, 2-(N,N-diethylcarbamoyl)ethoxy and 3-(N,N-dimethylcarbamoyl)propoxy; when it is 2-(1-4C)alkylaminoethoxy is, for example, 2-(methylamino)ethoxy, 2-(ethylamino)ethoxy and 2-(propylamino)ethoxy; when it is 2-di-[(1-4C)alkyl]aminoethoxy is, for example, 2-(dimethylamino)ethoxy, 2-(N-ethyl-N-methylamino)ethoxy, 2-(diethylamino)ethoxy and 2-(dipropylamino)ethoxy; when it is (1-4C)alkoxycarbonyl-(1-4C)alkoxy is, for example, methoxycarbonylmethoxy, ethoxycarbonylmethoxy, 1-methoxycarbonylethoxy, 2-methoxycarbonylethoxy, 2-ethoxycarbonylethoxy and 3-methoxycarbonylpropoxy; when it is halogeno-(1-4C)alkoxy is, for example, difluoromethoxy, trifluoromethoxy, 2-fluoroethoxy, 2-chloroethoxy, 2-bromoethoxy, 3-fluoropropoxy, 3-chloropropoxy and 2-chloro-2,1,1-trifluoroethoxy; when it is (2-4C)alkanoyloxy-(2-4C)alkoxy is, for example, 2-acetoxyethoxy, 2-propionyloxyethoxy, 2-butyryloxyethoxy and 3-acetoxypropoxy; when it is 2-(1-4C)alkoxyethoxy is, for example, 2-methoxyethoxy, 2-ethoxyethoxy; when it is carboxy-(1-4C)alkoxy is, for example, carboxymethoxy, 1-carboxyethoxy, 2-carboxyethoxy and 3-carboxypropoxy; when it is (3-5C)alkenyloxy is, for example, allyloxy; when it is (3-5C)alkynyloxy is, for example, propynyloxy; when it is (1-4C)alkylthio is, for example, methylthio, ethylthio or propylthio; when it is (1-4C)alkyylsulphinyl is, for example, methylsulphinyl, ethylsulphinyl or propylsulphinyl; when it is (1-4C)alkylsulphonyl is, for example, methylsulphonyl, ethylsulphonyl or propylsulphonyl; when it is N-(1-4C)alkylcarbamoyl is, for example N-methylcarbamoyl, N-ethylcarbamoyl and N-propylcarbamoyl; when it is N,N-di-[(1-4C)alkyl]-carbamoyl is, for example N,N-dimethylcarbamoyl, N-ethyl-N-methylcarbamoyl and N,N-diethylcarbamoyl; when it is (1-4C)alkylamino or (1-3C)alkylamino is, for example, methylamino, ethylamino or propylamino; when it is di-[(1-4C)alkyl]amino or di-[(1-3C)alkyl]amino is, for example, dimethylamino, N-ethyl-N-methylamino, diethylamino, N-methyl-N-propylamino or dipropylamino; when it is (2-4C)alkanoylamino is, for example, acetamido, propionamido or butyramido; when it is phenyl-(1-4C)alkyl is, for example benzyl or 2-phenylethyl; when it is phenyl-(1-4C)alkoxy is, for example benzyloxy; when it is xe2x80x94NHCO(1-4C)alkyl is, for example acetamido; when it is N-phthalimido-(1-4C)alkyl is, for example 2-(N-phthalimido)ethyl or 3-(N-phthalimido)propyl.
A suitable pharmaceutically-acceptable salt of a pyrimidine derivative of the invention is, for example, an acid-addition salt of a pyrimidine derivative of the invention which is sufficiently basic, for example, an acid-addition salt with, for example, an inorganic or organic acid, for example hydrochloric, hydrobromic, sulphuric, phosphoric, trifluoroacetic, citric or maleic acid. In addition a suitable pharmaceutically-acceptable salt of a pyrimidine derivative of the invention which is sufficiently acidic is an alkali metal salt, for example a sodium or potassium salt, an alkaline earth metal salt, for example a calcium or magnesium salt, an ammonium salt or a salt with an organic base which affords a physiologically-acceptable cation, for example a salt with methylamine, dimethylamine, trimethylamine, piperidine, morpholine, tris-(2-hydroxyethyl)amine, N-methylpiperidine, N-ethylpiperidine, procaine, dibenzylamine, N,N-dibenzylethylamine, N-methyl deglucamine and amino acids such as lysine. There may be more than one cation or anion depending on the number of charged functions and the valency of the cations or anions. A preferred pharmaceutically-acceptable salt is the sodium salt.
However, to facilitate isolation of the salt during preparation, salts which are less soluble in the chosen solvent may be preferred whether pharmaceutically-acceptable or not.
In another embodiment there is provided a compound of formula (I) wherein
R1 is selected from (1-6C)alkyl [optionally substituted by one or two substituents independently selected from halo, amino, (1-4C)alkylamino, di-[(1-4C)alkyl]amino, hydroxy, cyano, (1-4C)alkoxy, (1-4C)alkoxycarbonyl, carbamoyl, xe2x80x94NHCO(1-4C)alkyl, trifluoromethyl, phenylthio, phenoxy], benzyl, (3-5C)alkenyl [optionally substituted by up to three halo substituents, or by one trifluoromethyl substituent, or one phenyl substituent], N-phthalimido-(1-4C)alkyl, (3-5C)alkynyl and (3-6C)cycloalkyl-(1-6C)alkyl;
wherein any phenyl or benzyl group in R1 is optionally substituted by up to three substituents independently selected from halogeno, hydroxy, nitro, amino, (1-3C)alkylamino, di-[(1-3C)alkyl]amino, cyano, trifluoromethyl, (1-3C)alkyl [optionally substituted by 1 or 2 substituents independently selected from halogeno, cyano, amino, (1-3C)alkylamino, di-[(1-3C)alkyl]amino, hydroxy and trifluoromethyl], (3-5C)alkenyl [optionally substituted by up to three halo substituents, or by one trifluoromethyl substituent], (3-5C)alkynyl, (1-3 C)alkoxy, xe2x80x94SH, xe2x80x94S-(1-3 C)alkyl, carboxy, (1-3C)alkoxycarbonyl;
Q1 and Q2 are both phenyl;
and one or both of Q1 and Q2 bears on any available carbon atom one substituent of the formula (Ia) and Q2 may bear on any available carbon atom further substituents of the formula (Ia) [provided that when present in Q1 the substituent of formula (Ia) is not adjacent to the xe2x80x94NHxe2x80x94 link];
wherein X is CH2, O, NH or S; Y is H or as defined for Z; Z is OH, SH, NH2, (1-4C)alkoxy, (1-4C)alkylthio, xe2x80x94NH(1-4C)alkyl, [N[(1-4C)alkyl]2, pyrrolidin-1-yl, piperidin-1-yl, piperazin-1-yl, morpholino or thiomorpholino; n is 1, 2 or 3; n is 1, 2 or 3;
and Q1 and Q2 may each optionally bear on any available carbon atom up to four substituents independently selected from halogeno, hydroxy, thio, nitro, carboxy, cyano, (2-4C)alkenyl [optionally substituted by up to three halo substituents, or by one trifluoromethyl substituent], (2-4C)alkynyl, (1-5C)alkanoyl, (1-4C)alkoxycarbonyl, (1-6C)alkyl, hydroxy-(1-3C)alkyl, fluoro-(1-4C)alkyl, amino-(1-3C)alkyl, (1-4C)alkylamino-(1-3 C)alkyl, di-[(1-4C)alkyl]amino-(1-3C)alkyl, cyano-(1-4C)alkyl, (2-4C)alkanoyloxy-(1-4C)-alkyl, (1-4C)alkoxy-(1-3C)alkyl, carboxy-(1-4C)alkyl, (1-4C)alkoxycarbonyl-(1-4C)alkyl, carbamoyl-(1-4C)alkyl, N-(1-4C)alkylcarbamoyl-(1-4C)alkyl, N,N-di-d[(1-4C)alkyl]-carbamoyl-(1-4C)alkyl, pyrrolidin-1-yl-(1-3 C)alkyl, piperidin-1-yl-(1-3C)alkyl, piperazin-1-yl-(1-3C)alkyl, morpholino-(1-3C)alkyl, thiomorpholino-(1-3C)alkyl, piperazin-1-yl, morpholino, thiomorpholino, (1-4C)alkoxy, cyano-(1-4C)alkoxy, carbamoyl-(1-4C)alkoxy, N-(1-4C)alkylcarbamoyl-(1-4C)alkoxy, N,N-di-[(1-4C)alkyl]-carbamoyl-(1-4C)alkoxy, 2-aminoethoxy, 2-(1-4C)alkylaminoethoxy, 2-di-[(1-4C)alkyl]aminoethoxy, (1-4C)alkoxycarbonyl-(1-4C)alkoxy, halogeno-(1-4C)alkoxy, 2-hydroxyethoxy, (2-4C)alkanoyloxy-(2-4C)alkoxy, 2-(1-4C)alkoxyethoxy, carboxy-(1-4C)alkoxy, (3-5C)alkenyloxy, (3-5C)alkynyloxy, (1-4C)alkylthio, (1-4C)alkylsulphinyl, (1-4C)alkylsulphonyl, ureido (H2Nxe2x80x94COxe2x80x94NHxe2x80x94), (1-4C)alkylNHxe2x80x94COxe2x80x94NHxe2x80x94, di-[(1-4C)alkyl]-Nxe2x80x94COxe2x80x94NHxe2x80x94, (1-4C)alkylNHxe2x80x94COxe2x80x94N[(1-4C)alkyl]-, di-((1-4C)alkyl]Nxe2x80x94COxe2x80x94N[(1-4C)alkyl]-, carbamoyl, N-[(1-4C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, amino, (1-4C)alkylamino, di-[(1-4C)alkyl]amino, (2-4C)alkanoylamino,
and also independently, or in addition to the above substituents, Q1 and/or Q2 may optionally bear on any available carbon atom up to two further substituents independently selected from phenyl-(1-4C)alkyl, phenyl-(1-4C)alkoxy, phenyl, naphthyl, benzoyl and a 5- or 6-membered aromatic heterocycle (linked via a ring carbon atom and containing one to three heteroatoms independently selected from oxygen, sulphur and nitrogen); wherein said naphthyl, phenyl, benzoyl, 5- or 6-membered aromatic heterocyclic substituents and the phenyl group in said phenyl-(1-4C)alkyl and phenyl-(1-4C)alkoxy substituents may optionally bear one or two substituents independently selected from halogeno, (1-4C)alkyl and (1-4C)alkoxy; or a pharmaceutically-acceptable salt or in-vivo-hydrolysable ester thereof.
In a further embodiment there is provided a compound of formula (I) wherein
R1 is selected from (1-6C)alkyl [optionally substituted by one or two substituents independently selected from halo, amino, (1-4C)alkylamino, di-(1-4C)alkylamino, hydroxy, cyano, (1-4C)alkoxy, (1-4C)alkoxycarbonyl and carbamoyl], benzyl, (2-4C)alkenyl, (2-5C)alkynyl and (3-6C)cycloalkyl-(1-6C)alkyl;
Q1 and Q2 are both phenyl;
and one or both of Q1 and Q2 bears on any available carbon atom that is not adjacent to the xe2x80x94NHxe2x80x94 or xe2x80x94NR1xe2x80x94 link one or more substituents of the formula (Ia)
wherein X is CH2, O, NH or S; Y is H or as defined for Z; Z is OH, SH, NH2, (1-4C)alkoxy, (1-4C)alkylthio, xe2x80x94NH(1-4C)alkyl, xe2x80x94N [(1-4C)alkyl]2, pyrrolidin-1-yl, piperidin-1-yl, piperazin-1-yl, morpholino or thiomorpholino; n is 1, 2 or 3; m is 1, 2 or 3;
and Q1 and Q2 may each optionally bear on any available carbon atom up to four substituents independently selected from halogeno, hydroxy, oxo, thioxo, nitro, carboxy, cyano, (2-4C)alkenyl, (2-4C)alkynyl, (1-5C)alkanoyl, (1-4C)alkoxycarbonyl, (1-4C)alkyl, hydroxy-(1-3 C)alkyl, fluoro-(1-4C)alkyl, amino-(1-3 C)alkyl, (1-4C)alkylamino-(1-3C)alkyl, di-[(1-4C)alkyl]amino-(1-3C)alkyl, cyano-(1-4C)alkyl, (2-4C)alkanoyloxy-(1-4C)-alkyl, (1-4C)alkoxy-(1-3C)alkyl, carboxy-(1-4C)alkyl, (1-4C)alkoxycarbonyl-(1-4C)alkyl, carbamoyl-(1-4C)alkyl, N-(1-4C)alkylcarbamoyl-(1-4C)alkyl, N,N-di-[(1-4C)alkyl]-carbamoyl-(1-4C)alkyl, pyrrolidin-1-yl-(1-3 C)alkyl, piperidin-1-yl-(1-3 C)alkyl, piperazin-1-yl-(1-3C)alkyl, morpholino-(1-3 C)alkyl, thiomorpholino-(1-3C)alkyl, (1-4C)alkoxy, cyano-(1-4C)alkoxy, carbamoyl-(1-4C)alkoxy, N-(1-4C)alkytcarbamoyl-(1-4C)alkoxy, N,N-di-[(1-4C)alkyl]-carbamoyl-(1-4C)alkoxy, 2-aminoethoxy, 2-(1-4C)alkylaminoethoxy, 2-di-[(1-4C)alkyl]aminoethoxy, (1-4C)alkoxycarbonyl-(1-4C)alkoxy, halogeno-(1-4C)alkoxy, 2-hydroxyethoxy, (2-4C)alkanoyloxy-(2-4C)alkoxy, 2-(1-4C)alkoxyethoxy, carboxy-(1-4C)alkoxy, (2-4C)alkenyloxy, (2-4C)alkynyloxy, (1-4C)alkylthio, (1-4C)alkylsulphinyl, (1-4C)alkylsulphonyl, ureido, carbamoyl, N-[(1-4C)alkyl]carbamoyl, N,N-di-[(1-4C)alkyl]carbamoyl, amino, (1-4C)alkylamino, di-[(1-4C)alkyl]amino, (2-4C)alkanoylamino, phenyl-(1-4C)alkyl, phenyl-(1-4C)alkoxy, phenyl, naphthyl, benzoyl and a 5- or 6-membered aromatic heterocycle (linked via a ring carbon atom and containing one to three heteroatoms independently selected from oxygen, sulphur and nitrogen); wherein said naphthyl, phenyl, benzoyl, 5- or 6-membered aromatic heterocyclic substituents and the phenyl group in said phenyl-(1-4C)alkyl and phenyl-(1-4C)alkoxy substituents may optionally bear one or two substituents independently selected from halogeno, (1-4C)alkyl and (1-4C)alkoxy; or a pharmaceutically-acceptable salt or in-vivo-hydrolysable ester thereof.
The compounds of the formula (I) may be administered in the form of a pro-drug which is broken down in the human or animal body to give a compound of the formula (I). A prodrug may be used to alter or improve the physical and/or pharmacokinetic profile of the parent compound and can be formed when the parent compound contains a suitable group or substituent which can be derivatised to form a prodrug. Examples of pro-drugs include in-vivo hydrolysable esters of a compound of the formula (I) or a pharmaceutically-acceptable salt thereof.
Various forms of prodrugs are known in the art, for examples see:
a) Design of Prodrugs, edited by H. Bundgaard, (Elsevier, 1985) and Methods in Enzymology, Vol. 42, p. 309-396, edited by K. Widder, et al. (Academic Press, 1985);
b) A Textbook of Drug Design and Development, edited by Krogsgaard-Larsen and H. Bundgaard, Chapter 5 xe2x80x9cDesign and Application of Prodrugsxe2x80x9d, by H. Bundgaard p. 113-191 (1991);
c) H. Bundgaard, Advanced Drug Delivery Reviews, 8, 1-38 (1992);
d) H. Bundgaard, et al., Journal of Pharmaceutical Sciences, 77, 285 (1988); and
e) N. Kakeya, et al., Chem Pharm Bull, 32, 692 (1984).
An in-vivo hydrolysable ester of a compound of the formula (I) or a pharmaceutically-acceptable salt thereof containing carboxy or hydroxy group is, for example, a pharmaceutically-acceptable ester which is hydrolysed in the human or animal body to produce the parent acid or alcohol. Suitable pharmaceutically-acceptable esters for carboxy include (1-6C)alkoxymethyl esters for example methoxymethyl, (1-6C)alkanoyloxymethyl esters for example pivaloyloxymethyl, phthalidyl esters, (3-8C)cycloalkoxycarbonyloxy-(1-6C)alkyl esters for example 1-cyclohexylcarbonyloxyethyl; 1,3-dioxolan-2-onylmethyl esters for example 5-methyl-1,3-dioxoan-ylmethyl; and (1-6C)alkoxycarbonyloxyethyl esters for example 1-methoxycarbonyloxyethyl and may be formed at any carboxy group in the compounds of this invention.
An in-vivo hydrolysable ester of a compound of the formula (I) or a pharmaceutically-acceptable salt thereof containing a hydroxy group or groups includes inorganic esters such as phosphate esters (including phosphoramidic cyclic esters) and xcex1-acyloxyalkyl ethers and related compounds which as a result of the in-vivo hydrolysis of the ester breakdown to give the parent hydroxy group/s. Examples of xcex1-acyloxyalkyl ethers include acetoxymethoxy and 2,2-dimethylpropionyloxymethoxy. A selection of in-vivo hydrolysable ester forming groups for hydroxy include (1-10C)alkanoyl, benzoyl, phenylacetyl and substituted benzoyl and phenylacetyl, (1-10C)alkoxycarbonyl (to give alkyl carbonate esters), di-(1-4C)alkylcarbamoyl and N-(di-(1-4C)alkylaminoethyl)-N-(1-4C)alkylcarbamoyl (to give carbamates), di-(1-4C)alkylaminoacetyl and carboxyacetyl. Examples of substituents on benzoyl include chloromethyl, aminomethyl, (1-4C)alkylaminomethyl and di-((1-4C)alkyl)aminomethyl, and morpholino or piperazino linked from a ring nitrogen atom via a methylene linking group to the 3- or 4-position of the benzoyl ring.
Certain suitable in-vivo hydrolysable esters of a compound of the formula (I) are described within the definitions listed in this specification. Further suitable in-vivo hydrolysable esters of a compound of the formula (I) are described as follows. For example, a 1,2-diol may be cyclised to form a cyclic ester of formula (PD1) or a pyrophosphate of formula (PD2): 
Esters of compounds of formula (I) wherein the HOxe2x80x94 function/s in (PD1) and (PD2) are protected by (1-4C)alkyl, phenyl or benzyl are useful intermediates for the preparation of such pro-drugs.
Further in-vivo hydrolysable esters include phosphoramidic esters, and also compounds of formula (I) in which any free hydroxy group independently forms a phosphoryl (npd is 1) or phosphiryl (npd is 0) ester of the formula (PD3): 
Useful intermediates for the preparation of such esters include compounds containing a group/s of formula (PD3) in which either or both of the xe2x80x94OH groups in (PD3) is independently protected by (1-4C)alkyl, phenyl or phenyl-(1-4C)alkyl (such phenyl groups being optionally substituted by 1 or 2 groups independently selected from (1-4C)alkyl, nitro, halo and (1-4C)alkoxy).
Thus, prodrugs containing groups such as (PD1), (PD2) and (PD3) may be prepared by reaction of a compound of formula (I) containing suitable hydroxy group/s with a suitably protected phosphorylating agent (for example, containing a chloro or dialkylamrino leaving group), followed by oxidation (if necessary) and deprotection.
When a compound of formula (I) contains a number of free hydroxy group, those groups not being converted into a prodrug functionality may be protected (for example, using a t-butyl-trimethylsilyl group), and later deprotected. Also, enzymatic methods may be used to selectively phosphorylate or dephosphorylate alcohol functionalities.
Where pharmaceutically-acceptable salts of an in-vivo hydrolysable ester may be formed this is achieved by conventional techniques. Thus, for example, compounds containing a group of formula (PD1), (PD2) and/or (PD3) may ionise (partially or fully) to form salts with an appropriate number of counter-ions. Thus, by way of example, if an in-vivo hydrolysable ester prodrug of a compound of formula (I) contains two (PD3) groups, there are four HOxe2x80x94Pxe2x80x94 functionalities present in the overall molecule, each of which may form an appropriate salt (i.e. the overall molecule may form, for example, a mono-, di-, tri- or tetra-sodium salt).
Some compounds of the formula (I) may have chiral centres and/or geometric isomeric centres (E- and Z-isomers), and it is to be understood that the invention encompasses all such optical, diastereo-isomers and geometric isomers, and mixtures thereof, that possess CDK inhibitory activity.
The invention relates to any and all tautomeric forms of the compounds of the formula (I) that possess CDK inhibitory activity.
It is also to be understood that certain compounds of the formula (I) can exist in solvated as well as unsolvated forms such as, for example, hydrated forms. It is to be understood that the invention encompasses all such solvated forms which possess CDK inhibitory activity.
Particular preferred compounds of the invention comprise a pyrimidine derivative of the formula (I), or pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof, wherein R1, Q1, Q2, X, Y, Z, m and n have any of the meanings defined hereinbefore, or any of the following values. Such values may be used where appropriate with any of the definitions, claims or embodiments defined hereinbefore or hereinafter.
(a0) When Q1 or Q2 is indanyl or 1,2,3,4-tetrahydronaphthyl, it is linked via the unsaturated ring; preferably Q1 and/or Q2 are (both) phenyl;
(a1) In another embodiment R1 is preferably benzyl, (3-5C)alkynyl (especially propyn-2-yl), (3-6C)cycloalkyl-(1-6C)alkyl (especially cyclopropylmethyl), (1-4C)alkyl [optionally substituted by one or two substituents selected from hydroxyy, amino, halo, trifluoromethyl and cyano] or (3-5C)alkenyl substituted by one to three halo groups;
(b) R1 is preferably benzyl, (3-5C)alkynyl (especially propyn-2-yl), (3-6C)cycloalkyl-(1-6C)alkyl (especially cyclopropylmethyl), (1-4C)alkyl [optionally substituted by one substituent selected from hydroxy, amino, halo, trifluoromethyl and cyano] or (3-5C)alkenyl substituted by one halo group;
(c) R1 is more preferably (3-5C)alkynyl (especially propyn-2-yl) or (1-4C)alkyl [optionally substituted by trifluoromethyl or cyano] or (3-5C)alkenyl substituted by one bromo group;
(d) R1 is most preferably propyn-2-yl, (1-4C)alkyl substituted by one trifluoromethyl or one cyano group (especially cyanomethyl or 2-cyanoethyl) or (3-5C)alkenyl substituted by one bromo group (especially xe2x80x94CH2CHxe2x95x90CHBr);
(e) R1 is most especially preferred as xe2x80x94CH2CHxe2x95x90CHBr, xe2x80x94CH2CH2CH2CF3 or xe2x80x94CH2CHxe2x95x90CH-phenyl;
(e1) In another embodiment R1 is preferred as propyn-2-yl, cyanomethyl, 2-cyanoethyl, xe2x80x94CH2CHxe2x95x90CHBr or xe2x80x94CH2CH2CH2CF3 (especially xe2x80x94CH2CH2CH2CF3);
(f) In one embodiment Z is preferably xe2x80x94NH(1-4C)alkyl, xe2x80x94N[(1-4C)alkyl]2, xe2x80x94NH-(3-8C)cycloalkyl, pyrrolidin-1-yl, piperidin-1-yl, piperazin-1-yl [optionally substituted in the 4-position by (1-4C)alkyl or (1-4C)alkanoyl], morpholino or thiomorpholino; or alternatively Z is NH2;
(f1) In one embodiment Y is preferably H, OH, SH, NH2, (1-4C)alkoxy, (1-4C)alkylthio, xe2x80x94NH(1-4C)alkyl, xe2x80x94N[(1-4C)alkyl]2or xe2x80x94NH-(3-8C)cycloalkyl; especially H or OH;
(f2) In one embodiment X is preferably O or NH or NRx; least preferred is X as S;
(f3) Preferably n+m is less than 5;
(f3) Preferably in the substituent of formula (Ia) X is O, Y is H or OH and Z is xe2x80x94NH(1-4C)alkyl, xe2x80x94N[(1-4C)alkyl]2 or xe2x80x94NH-(3-8C)cycloalkyl; preferably n is 1 and m is 1;
(f4) In another embodiment in the substituent of formula (Ia) X is O, Y is OH and Z is xe2x80x94N[(1-4C)alkyl]2; preferably n is 1 and m is 1;
(g) Most preferably the substituent of formula (Ia) is 3-dimethylamino-2-hydroxypropoxy;
(h) Preferably there is one substituent of formula (Ia), and this substituent is in ring Q1 (i.e a ring linked via xe2x80x94NHxe2x80x94);
(i) When the substituent of formula (Ia) is in Q1 it must be in either the para- or meta-position relative to the xe2x80x94NHxe2x80x94, preferably in the para-position;
(j) Preferably Q1 bears no further substituents (other than (Ia)); preferable further substituents for Q2include halo, hydroxy-(1-3C)alkyl, fluoro-(1-4C)alkyl (especially trifluoromethyl), morpholino and (1-4C)alkyl (especially methyl);
(k) More preferable further substituents for Q2 include halo, morpholino and (1-4C)alkyl (especially methyl);
(l) Preferably the ring Q1 or Q2 not bearing the substituent of formula (Ia) is substituted by one or two further substituents, preferably halo, morpholino and/or (1-4C)alkyl (especially methyl);
(m) Most preferably the ring Q1 bears the substituent of formula (Ia) and Q2 is substituted by one or two further substituents, selected preferably from halo, hydroxy-(1-3 C)alkyl, fluoro-(1-4C)alkyl (especially trifluoromethyl), morpholino and (1-4C)alkyl (especially methyl).
A preferred compound of the invention is a pyrimidine derivative of the formula (I), or pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof as claimed in any of claims 1 to 5 and wherein (i) Q2 does not bear any optional further substituents of formula (Ia) and/or (ii) there is one substituent of formula (Ia), borne by Q1 and/or (iii) in claims 1 or 2 Q1 does not bear any of the additional two further substituents that are listed.
A further preferred compound of the invention is a pyrimidine derivative of the formula (I), or pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof, wherein:
Q1 and Q2 are both phenyl;
R1 is (1-4C)alkyl substituted by one cyano group (especially cyanomethyl);
or alternatively R1 is xe2x80x94CH2CHxe2x95x90CHBr or xe2x80x94CH2CH2CH2CF3 (especially xe2x80x94CH2CH2CH2CF3) or xe2x80x94CH2CHxe2x95x90CH-phenyl;
Q1 bears one substituent of formula (Ia) (especially 3-dimethylamino-2-hydroxypropoxy), preferably in the para-position;
Q2 bears one or two substituents independently selected from halo, morpholino and (1-4C)alkyl (especially methyl).
A specific preferred compound of the invention is the following pyrimidine derivative of the formula (I):
4-{4-[3-(N,N-Dimethyl)amino-2-hydroxy-propoxy]anilino}-6-(N-cyanomethyl-2-bromo-4-methylanilino)pyrimidine;
4-{4-[3-(N,N-Dimethyl)amino-2-hydroxy-propoxy]anilin}-6-(N-cyanomethyl-2-chloro-5-methylanilino)pyrimidine;
4-{4-[3-(N,N-Dimethyl)amino-2-hydroxy-propoxy]anilino}-6-(N-(3-phenylprop-2-enyl)-2-bromo-4-methylanilino)pyrimidine; or pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof.
Other specific preferred compounds of the invention are the pyrimidine derivatives of the formula (I), described in Examples 6, 10, 19 and 20, or pharmaceutically-acceptable salts or in-vivo hydrolysable esters thereof.
Process Section
A pyrimidine derivative of the formula (I), or a pharmaceutically-acceptable salt or an in vivo hydrolysable ester thereof, may be prepared by any process known to be applicable to the preparation of chemically-related compounds. Such processes, when used to prepare a pyrimidine derivative of the formula (I), or a pharmaceutically-acceptable salt or an in vivo hydrolysable ester thereof, are provided as a further feature of the invention and are illustrated by the following representative examples in which, unless otherwise stated R1, Q1, Q2, X, Y, Z, m and n have any of the meanings defined hereinbefore for a pyrimidine derivative of the formula (I) and unless another substituent is drawn on ring Q1 or Q2 the ring may bear any of the substituents described hereinbefore (optionally protected as necessary). Where a substituent is drawn on ring Q1, this includes (unless stated otherwise) the possibilities of the substituent/s being on ring Q2 in addition to, or instead of the substituent being on ring Q1. Where X is defined in this process section as NH it is to be understood that this also includes the possibility of X as NRx.
Necessary starting materials may be obtained by standard procedures of organic chemistry (see, for example Advanced Organic Chemistry (Wiley-interscience), Jerry Marchxe2x80x94also useful for general guidance on reaction conditions and reagents). The preparation of such starting materials is described within the accompanying non-limiting processes and Examples. Alternatively necessary starting materials are obtainable by analogous procedures to those illustrated which are within the ordinary skill of an organic chemist.
Thus, as a further feature of the invention there are provided the following processes which comprises of:
a) reacting a pyrimidine of formula (II): 
xe2x80x83wherein L is a displaceable group as defined below, with a compound of formula (III): 
b) reaction of a pyrimidine of formula (IV): 
xe2x80x83wherein L is a displaceable group as defined below, with a compound of formula (V): 
c) reacting a pyrimidine of formula (VI): 
xe2x80x83with a compound of formula (VII)
R1xe2x80x94Lxe2x80x83xe2x80x83(VII)
wherein L is a displaceable group as defined below;
d) for compounds of formula (I) where n=1, 2 or 3; m=1 and Y is OH, NH, or SH, reaction of a 3-membered heteroalkyl ring of formula (VIII): 
xe2x80x83wherein A is O, S or NH;
with a nucleophile of formula (IX):
Zxe2x80x94Dxe2x80x83xe2x80x83(IX)
xe2x80x83wherein D is H or a suitable counter-ion;
e) for compounds of formula (I) where X is oxygen, by reaction of an alcohol of formula (X): 
xe2x80x83with an alcohol of formula (XI): 
f) for compounds of formula (I) wherein X is CH2, O, NH or S; Y is OH and In is 2 or 3;
reaction of a compound of formula (XII): 
xe2x80x83wherein xe2x80x94OLg is a leaving group such as mesylate or tosylate; with a nucleophile of formula Zxe2x80x94D (IX) wherein D is H or a suitable counter-ion;
g) for compounds of formula (I) wherein X is CH2, O, NH or S; Y is H; n is 1, 2 or 3 and m is 1, 2 or 3:
reaction of a compound of formula (XIII): 
xe2x80x83wherein xe2x80x94OLg is a leaving group such as mesylate or tosylate; with a nucleophile of formula Zxe2x80x94D (IX) wherein D is H or a suitable counter-ion;
h) for compounds of formula (I) wherein X is O, NH or S; Y is H; n is 1, 2 or 3 and m is 1, 2 or 3; reaction of a compound of formula (XIV) with a compound of formula (XV): 
xe2x80x83or
i) for compounds of formula (I) in which Z is SH, by conversion of a thioacetate group in a corresponding compound; and thereafter if necessary:
(i) converting a compound of the formula (I) into another compound of the formula (I);
(ii) removing any protecting groups;
(iii) forming a pharmaceutically acceptable salt or in vivo hydrolysable ester.
L is a displaceable group, suitable values for L are for example, a halogeno or sulphonyloxy group, for example a chloro, bromo, methanesulphonyloxy or toluene-4-sulphonyloxy group.
D is hydrogen or a counter-ion. When D is a counter-ion, suitable values for D include sodium and potassium.
Specific reaction conditions for the above reactions are as follows:
Process a)
Pyrimidines of formula (II) and compounds of formula (III) may be reacted together
i) optionally in the presence of a suitable acid, for example an inorganic acid such as hydrochloric acid or sulphuric acid, or an organic acid such as acetic acid or formic acid. The reaction is preferably carried out in a suitable inert solvent or diluent, for example dichloromethane (DCM), acetonitrile, butanol, tetramethylene sulphone, tetrahydrofuran, 1,2-dimethoxyethane, N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidin-2-one, and at a temperature in the range, for example, 0xc2x0 to 150xc2x0 C., conveniently at or near reflux temperature; or
ii) under standard Buchwald conditions (for example see J. Am. Chem. Soc., 118, 7215; J. Am. Chem. Soc., 119, 8451; J. Org. Chem., 62, 1568 and 6066) for example in the presence of palladium acetate, in a suitable solvent for example an aromatic solvent such as toluene, benzene or xylene, with a suitable base for example an inorganic base such as caesium carbonate or an organic base such as potassium-t-butoxide, in the presence of a suitable ligand such as 2,2xe2x80x2-bis(diphenylphosphino)-1,1xe2x80x2-binaphthyl and at a temperature in the range of 25 to 80xc2x0 C.
Pyrimidines of the formula (II) may be prepared according to the following scheme: 
Compounds of formula (III) are commercially available or are prepared by processes known in the art.
Process b)
Pyrimidines of formula (IV) and compounds of formula (V) may be reacted together
i) in the presence of a suitable solvent for example a ketone such as acetone or an alcohol such as ethanol or butanol or an aromatic hydrocarbon such as toluene or N-methyl pyrrolidine, or a solvent such as tetramethylene sulphone, optionally in the presence of a suitable acid such as those defined above and at a temperature in the range of 0xc2x0 C. to reflux, preferably reflux; or
ii) under standard Buchwald conditions as described above,
Pyrimidines of formula (IV) are prepared according to the following scheme: 
wherein L is a displaceable group as defined above.
The compounds of formula (V) are commercially available or are prepared by processes known in the art.
Process c)
Pyrimidines of formula (VI) and compounds of formula (VII) are reacted together in the presence of a suitable base such as sodium hydride or potassium carbonate or potassium tert-butoxide and a suitable solvent such as N,N-dimethylformamide, dimethyl sulfoxide or tetrahydrofuran at a temperature in the range of xe2x88x9220xc2x0 to 110xc2x0 C., preferably xe2x88x9220xc2x0 to 60xc2x0 C.
Compounds of formula (VI) may be prepared according to the following scheme: 
Process d)
Three membered heteroalkyl rings of formula (VIII) and nucleophiles of formula (IX) are reacted together at a temperature in the range of 20xc2x0 to 100xc2x0 C., preferably 20xc2x0 to 50xc2x0 C., optionally in the presence of a suitable solvent, for example N,N-dimethylformamide, dimethyl sulfoxide or tetrahydrofuran.
Compounds formula (VIII) may be prepared according to the following schemes:
Scheme I) for compounds of formula (VIII) where A is O, and X is not carbon: 
The conversion of (VIIIB) to (VIII) may also be achieved by reaction with Brxe2x80x94(CH2)nxe2x80x94CHO, or an equivalent ester, in DMF and the presence of a base, followed by reaction with a sulfur ylide such as (Me2SOCH2) in an inert solvent such as THF (see Scheme V); followed by reaction with R1xe2x80x94L.
Scheme II) for compounds of formula (VIII) where A is NH, and X is not carbon: 
(for PhINTs see, for example. Tet.Let., 1997, 38 (39), 6897-6900; compounds of formula (VIIIC) may also be oxidised to the epoxide using conditions similar to that in Scheme IV) below);
Scheme III) for compounds of formula (VIII) where A is S, and X is not carbon: 
(for example see Synlett. 1994, 267-268);
Scheme IV) For compounds of formula (VIII) where X is carbon 
xe2x80x83wherein R3 together with the xe2x80x94COOxe2x80x94 group to which it is attached forms an ester moiety, for example a methyl ester or an ethyl ester.
Scheme V) For compounds of formula (VIII) wherein X is CH2, O, NH or S; Y is OH; n is 1, 2 or 3 and m is 1: 
(XB) is reacted with (IVC) (see Scheme I) and then R1xe2x80x94L to give (VIII).
An equivalent ester of (XA) may also be used. See also Russ.Chem. Rev. 47, 975-990, 1978.
Compounds of formula (VII), (IX), (VIIIA) and (VIIID) are commercially available or are prepared by processes known in the art.
Process e)
Alcohols of formula (X) and (XI) can be reacted together under standard Mitsunobu conditions. For example in the presence of diethyl azodicarboxylate and triphenyl phosphine, in a suitable solvent such as dichloromethane, toluene or tetrahydrofuran, and at a temperature in the range of 0xc2x0 to 80xc2x0 C., preferably in the range of 20xc2x0 to 60xc2x0 C.
Alcohols of formula (X) are made according to the process in Scheme I) above for the synthesis of intermediate (VIIIB) (where X is oxygen).
Alcohols of formula (XI) are commercially available or are made by processes known in the art.
In a process analogous to process e), compounds in which X is S may be prepared by reaction of a compound of formula (X) in which the hydroxy group is xe2x80x94SH, with a compound of formula (XI) in which the hyrdoxy group is a leaving group such as mesylate or tosylate.
Process f)
Compounds of formula (XII) wherein X is CH2, O, NH or S; Y is OH and m is 2 or 3 and nucleophiles of formula (IX) are reacted together at a temperature in the range of 20xc2x0 to 100xc2x0 C., preferably 20xc2x0 to 50xc2x0 C., optionally in the presence of a suitable solvent, for example N,N-dimethylformamide, dimethyl sulphoxide or tetrahydrofuran,and optionally in the presence of a suitable base, such as potassium carbonate.
Compounds of formula (XII) are prepared according to the following scheme (m is 2 or 3): 
The steps 1) and 2) in the final step may be reversed. A suitable base for step 2) is triethylamine.
Compounds of formula (XIIA) and (IX) are commercially available or are prepared by processes known in the art. For example, compounds of formula (XIIA) in which X is NH, O or S may be prepared by reaction of a compound of formula (VIIIA) with a suitable haloaldehyde or equivalent ester under standard conditions for such reactions.
Process g)
Compounds of formula (XIII) and nucleophiles of formula (IX) are reacted together as described for process f) above.
Compounds of formula (XIII) are prepared in an analogous manner to step 2) in the final step of the process for preparing compounds of formula (XII) above. The necessary primary alcohol starting materials are commercially available or are prepared by processes known in the art.
Process h)
Compounds of formula (XIV) and (XV) are reacted in an inert solvent such as DMF in the presence of a base such as potassium carbonate.
Compounds of formula (XIV) are prepared as described in Scheme I), but omitting the first stage of the final step (i.e. no reaction with the epoxide). Compounds of formula (XV) are commercially available or are prepared by processes known in the art.
Process i)
For the compounds of formula (I) in which Z is SH, the conversion of a thioacetate group in a corresponding compound is carried out as described herein for the conversion of compounds of formula (IJ) into (IK).
Suitable starting materials containing a thioacetate group are prepared from corresponding compounds containing a leaving group such as mesylate or tosylate (prepared using standard conditions from the corresponding hydroxy compound) using thiol acetic acid as described herein for the conversion of compounds of formula (IG) into (IJ).
Examples of conversions of a compound of formula (I) into another compound of formula (I) are:
Conversion i) conversion of R1 as a substituted side chain into another substituted side chain, for example: 
xe2x80x83wherein Ms is methanesulphonyl, and Nu is a nucleophile that introduces a substituent that is an optional substituent for R1 as defined in formula (I), preferably Nu is xe2x80x94NH2, xe2x80x94NHC1-4alkyl, xe2x80x94N(C1-4alkyl)2 or xe2x80x94CN (NB the hydroxyl moiety does not necessarily have to be on the terminal carbon as depicted above);
Conversion ii): conversion of one side chain of formula (Ia) into another side chain of formula (Ia), for example:
for compounds of formula (I) where Y is NH2 (depicted below using ammonia), (1-4C)alkoxy, (1-4C)alkylthio, xe2x80x94NH(1-4C)alkyl, xe2x80x94N[(1-4C)alkyl]2, pyrrolidin-1-yl, piperidin-1-yl, piperazin-1-yl, morpholino or thiomorpholino; 
or:
for compounds of formula (1) where Y is S: 
for compounds of formula (I) where Y is H: 
The skilled reader will appreciate that the manipulation of the side chain (Ia) described in Processes c), d), e), f), g) and h) and Conversion ii) above and of the sidechain R1 in Conversion i) above may also be performed on intermediates for example to make intermediates of formula (II), (IIA), (IIB), or (V). For example: 
It will be appreciated that certain of the various ring substituents in the compounds of the present invention may be introduced by standard aromatic substitution reactions or generated by conventional functional group modifications either prior to or immediately following the processes mentioned above, and as such are included in the process aspect of the invention. Such reactions and modifications include, for example, introduction of a substituent by means of an aromatic substitution reaction, reduction of substituents, alkylation of substituents and oxidation of substituents. The reagents and reaction conditions for such procedures are well known in the chemical art. Particular examples of aromatic substitution reactions include the introduction of a nitro group using concentrated nitric acid, the introduction of an acyl group using, for example, an acyl halide and Lewis acid (such as aluminium trichloride) under Friedel Crafts conditions; the introduction of an alkyl group using an alkyl halide and Lewis acid (such as aluminium trichloride) under Friedel Crafts conditions; and the introduction of a halogeno group. Particular examples of modifications include the reduction of a nitro group to an amino group by for example, catalytic hydrogenation with a nickel catalyst or treatment with iron in the presence of hydrochloric acid with heating; oxidation of alkylthio to alkylsulphinyl or alkylsulphonyl.
It will also be appreciated that in some of the reactions mentioned herein it may be necessary/desirable to protect any sensitive groups in the compounds. The instances where protection is necessary or desirable and suitable methods for protection are known to those skilled in the art. Conventional protecting groups may be used in accordance with standard practice (for illustration see T. W. Green, Protective Groups in Organic Synthesis, John Wiley and Sons, 1991). Thus, if reactants include groups such as amino, carboxy or hydroxy it may be desirable to protect the group in some of the reactions mentioned herein.
A suitable protecting group for an amino or alkylamino group is, for example, an acyl group, for example an alkanoyl group such as acetyl, an alkoxycarbonyl group, for example a methoxycarbonyl, ethoxycarbonyl or t-butoxycarbonyl group, an arylmethoxycarbonyl group, for example benzyloxycarbonyl, or an aroyl group, for example benzoyl. The deprotection conditions for the above protecting groups necessarily vary with the choice of protecting group. Thus, for example an acyl group such as an alkanoyl or alkoxycarbonyl group or an aroyl group may be removed for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an acyl group such as a t-butoxycarbonyl Croup may be removed, for example, by treatment with a suitable acid as hydrochloric, sulphuric or phosphoric acid or trifluoroacetic acid and an arylmethoxycarbonyl group such as a benzyloxycarbonyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-carbon, or by treatment with a Lewis acid for example boron tris(trifluoroacetate). A suitable alternative protecting group for a primary amino group is, for example, a phthaloyl group which may be removed by treatment with an alkylamine, for example dimethylaminopropylamine, or with hydrazine.
A suitable protecting group for a hydroxy group is, for example, an acyl group, for example an alkanoyl group such as acetyl, an aroyl group, for example benzoyl, or an arylmethyl group, for example benzyl. The deprotection conditions for the above protecting groups will necessarily vary with the choice of protecting group. Thus, for example, an acyl group such as an alkanoyl or an aroyl group may be removed, for example, by hydrolysis with a suitable base such as an alkali metal hydroxide, for example lithium or sodium hydroxide. Alternatively an arylmethyl group such as a benzyl group may be removed, for example, by hydrogenation over a catalyst such as palladium-on-carbon.
A suitable protecting group for a carboxy group is, for example, an esterifying group, for example a methyl or an ethyl group which may be removed, for example, by hydrolysis with a base such as sodium hydroxide, or for example a t-butyl group which may be removed, for example, by treatment with an acid, for example an organic acid such as trifluoroacetic acid, or for example a benzyl group which may be removed, for example, by hydrogenation over a catalyst such as palladium-on-carbon.
The protecting groups may be removed at any convenient stage in the synthesis using conventional techniques well known in the chemical art.
Many of the intermediates defined herein are novel, for example, those of the formula (II) and (IV) and these are provided as a further feature of the invention.
Assays
As stated hereinbefore the pyrimidine derivative defined in the present invention possesses anti-cell-proliferation activity such as anti-cancer activity which is believed to arise from the CDK inhibitory activity of the compound. These properties may be assessed, for example, using the procedure set out below:
CDK Inhibition Assay
The following abbreviations have been used:
HEPES is N-[2-Hydroxyethyl]piperazine-Nxe2x80x2-[2-ethanesulfonic acid]
DTT is Dithiothretiol
PMSF is Phenylmethylsulfonyl fluoride
The compounds were tested in an in vitro kinase assay in 96 well format using Scintillation Proximity Assay (SPAxe2x80x94obtained from Amersham) for measuring incorporation of [xcex3-33-P]-Adenosine Triphosphate into a test substrate (GST-Retinoblastoma). In each well was placed the compound to be tested (diluted in DMSO and water to correct, concentrations) and in control wells either p 16 as an inhibitor control or DMSO as a positive control.
Approximately 0.5 xcexcl of CDK4/Cyclin D1 partially-purified enzyme (amount dependent on enzyme activity) diluted in 25 xcexcl incubation buffer was added to each well then 20 xcexcl of GST-Rb/ATP/ATP33 mixture (containing 0.54 xcexcg GST-Rb and 0.2 xcexcM ATP and 0.14 xcexcCi [xcex3-33-P]-Adenosine Triphosphate), and the resulting mixture shaken gently, then incubated at room temperature for 60 minutes.
To each well was then added 150 xcexcL stop solution containing (0.8 mg/well of Protein A-PVT SPA bead (Amersham)), 20 pM/well of Anti-Glutathione Transferase, Rabbit IgG (obtained from Molecular Probes), 61 mM EDTA and 50 mM HEPES pH 7.5 containing 0.05% sodium azide.
The plates were sealed with Topseal-S plate sealers, left for two hours then spun at 2500 rpm, 1124xc3x97g., for 5 minutes. The plates were read on a Topcount for 30 seconds per well.
The incubation buffer used to dilute the enzyme and substrate mixes contained 50 mM HEPES pH7.5, 10 mM MnCl2, 1 mM DTT, 100 xcexcM Sodium vanadate, 100 xcexcM NaF, 10 mM Sodium Glycerophosphate, BSA (1 mg/ml final).
As a control, another known inhibitor of CDK4 may be used in place of p16.
Test Substrate
In this assay only part of the retinoblastoma (Science 1987 Mar13;235(4794):1394-1399; Lee W. H., Bookstein R., Hong F., Young L. J., Shew J. Y., Lee E. Y.) was used, fused to a GST tag. PCR of retinoblastoma amino acids 379-928 (obtained from retinoblastoma plasmid ATCC pLRbRNL) was performed, and the sequence cloned into pGEX 2T fusion vector (Smith D. B. and Johnson, K. S. Gene 67, 31 (1988); which contained a tac promoter for inducible expression internal lac Iq gene for use in any E.Coli host, and a coding region for thrombin cleavagexe2x80x94obtained from Pharmacia Biotech) which was used to amplify amino acids 792-928. This sequence was again cloned into pGEX 2T.
The retinoblastoma 792-928 sequence so obtained was expressed in E.Coli (BL21 (DE3) pLysS cells ) using standard inducible expression techniques, and purified as follows.
E.coli paste was resuspended in 10 ml/g of NETN buffer (50 mM Tris pH 7.5, 120 mM NaCl, 1 mM EDTA, 0.5% v/v NP-40, 1 mM PMSF, 1 ug/ml leupeptin, 1 ug/ml aprotinin and 1 ug/ml pepstatin) and sonicated for 2xc3x9745 seconds per 100 ml homogenate. After centrifugation, the supernatant was loaded onto a 10 ml glutathione Sepharose column (Pharmacia Biotech. Herts. UK), and washed with NETN buffer. After washing with kinase buffer (50 mMN HEPES pH 7.5. 10 mM MgCl2, 1 mM DTT, 1 mM PMSF, 1 ug/ml leupeptin, 1 ug/ml aprotinin and 1 ug/ml pepstatin) the protein was eluted with 50 mM reduced glutathione in kinase buffer. Fractions containing GST-Rb(792-927) were pooled and dialysed overnight against kinase buffer. The final product was analysed by Sodium Dodeca Sulfate (SDS) PAGE (Polyacrylamide gel) using 8-16% Tris-Glycine gels (Novex, San Diego, USA).
CDK4 and Cyclin D1
CDK4 and Cyclin D1 were cloned from RNA from NICF-7 cell line (obtained from ATCC number:HTB22, breast adenocarcinoma line) as follows. The RNA was prepared from MCF-7 cells, then reverse transcribed using oligo dT primers. PCR was used to amplify the complete coding sequence of each gene [CDK4 amino acids 1-303; Ref. Cell 1992 Oct 16; 71(2): 323-334; Matsushime H., Ewen M. E., Stron D. K., Kato J. Y., Hanks S. K., Roussel M. F., Sherr C. J. and Cyclin D1 amino acids 1-296; Ref. Cold Spring Harb. Symp. Quant. Biol., 1991; 56:93-97; Amold A., Motokura T., Bloom T., Kronenburg, Ruderman J., Juppner H., Kim H. G.].
After sequencing the PCR products were cloned using standard techniques into the insect expression vector pVL1393 (obtained from Invitrogen 1995 catalogue number: V1392-20). The PCR products were then dually expressed [using a standard virus Baculogold co-infection technique] into the insect SF21 cell system (Spodoptera Frugiperda cells derived from ovarian tissue of the Fall Army Wormxe2x80x94commercially available).
The following Example provides details of the production of Cyclin D1/CDK4 in SF21 cells (in TC100+10% FBS(TCS)+0.2% Pluronic) having dual infection MOI 3 for each virus of Cyclin D1 and CDK4.
Example Production of Cyclin D1/CDK4
SF21 cells crown in a roller bottle culture to 2.33xc3x97106 cells/ml were used to inoculate 10xc3x97500 ml roller bottles at 0.2xc3x9710E6 cells/ml. The roller bottles were incubated on a roller rig at 28xc2x0 C.
After 3 days (72 hrs.) the cells were counted, and the average from 2 bottles found to be 1.86xc3x9710E6 cells/ml. (99% viable). The cultures were then infected with the dual viruses at an MOI 3 for each virus.
10xc3x97500 ml were infected with JS303 Cyclin D1 virus titrexe2x80x949xc3x9710E7 pfu/ml. JS304 CDK4 virus titrexe2x80x941xc3x9710E8 pfu/ml.             Cyclin      ⁢              xe2x80x83            ⁢      D1      ⁢              xe2x80x83            ⁢                        1.86          xc3x97          10          ⁢          E6          xc3x97          500          xc3x97          3                          0.9          xc3x97                      10            8                                =                  31        ⁢                  xe2x80x83                ⁢        ml        ⁢                  xe2x80x83                ⁢        of        ⁢                  xe2x80x83                ⁢        virus        ⁢                  xe2x80x83                ⁢        of        ⁢                  xe2x80x83                ⁢        each        ⁢                  xe2x80x83                ⁢        500        ⁢                  xe2x80x83                ⁢                  ml          .                      xe2x80x83                    ⁢          bottle          .                      
                    ⁢          CDK4                ⁢                  xe2x80x83                ⁢                              1.86            xc3x97            10            ⁢            E6            xc3x97            500            xc3x97            3                                1            xc3x97                          10              8                                          =              28        ⁢                  xe2x80x83                ⁢        ml        ⁢                  xe2x80x83                ⁢        of        ⁢                  xe2x80x83                ⁢        virus        ⁢                  xe2x80x83                ⁢        for        ⁢                  xe2x80x83                ⁢        each        ⁢                  xe2x80x83                ⁢        500        ⁢                  xe2x80x83                ⁢                  ml          .                      xe2x80x83                    ⁢          bottle          .                      ⁢      xe2x80x83  
The viruses were mixed together before addition to the cultures, and the cultures returned to the roller rig 28xc2x0 C.
After 3 days (72 hrs.) post infection the 5 Litres of culture was harvested. The total cell count at harvest was 1.58xc3x9710E6 cells/ml.(99% viable). The cells were spun out at 2500 rpm, 30 mins., 4xc2x0 C. in Heraeus Omnifuge 2.0 RS in 250 mls. lots. The supernatant was discarded.
20 pellets of xcx9c4xc3x9710E8 cells/pellet were snap frozen in LN2 and stored at xe2x88x9280xc2x0 C. in CCRF cold room. The SF21 cells were then hypotonically lysed by resuspending in lysis buffer (50 mM HEPES pH 7.5, 10 mM magnesium chloride, 1 mM DTT, 10 mM glycerophosphate, 0.1 mM PMSF, 0.1 mM sodium fluoride, 0.1 mM sodium orthovanadate, 5 ug/ml aprotinin, 5 ug/ml leupeptin and 20% w/v sucrose), and adding ice cold deionised water. After centrifugation, the supernatant was loaded onto a Poros HQ/M 1.4/100 anion exchange column (PE Biosystems, Hertford, UK). CDK4 and Cyclin D1 were coeluted with 375 mM NaCl in lysis buffer, and their presence checked by western blot, using suitable anti-CDK4 and anti-Cyclin D1 antibodies (obtained from Santa Cruz Biotechnology, California, US).
p16 Control (Nature 366.:704-707; 1993: Serrano M. Hannon G J. Beach D)
p16 (the natural inhibitor of CDK4/Cyclin D1) was amplified from HeLa cDNA (Hela cells obtained from ATCC CCL2, human epitheloid carcinoma from cervix; Cancer Res. 12: 264, 1952), cloned into pTB 375 NBSE which had a 5xe2x80x2 His tag, and transformed using standard techniques into BL21 (DE3) pLysS cells (obtained from Promega; Ref. Studier F. W. and Mtoffat B. A., J. Mol. Biol., 189, 113, 1986). A 1 liter culture was grown to the appropriate OD then induced with IPTG to express p16 overnight. The cells were then lysed by sonication in 50 mM sodium phoshate, 0.5 M sodium chloride, PMSF, 0.5 xcexcg/mL leupeptin and 0.5 xcexcg/mL aprotinin. The mixture was spun doen, the supernatant added to nickel chelate beads and mixed for 1xc2xd hours. The beads were washed in sodium phosphate, NaCl pH 6.0 and p16 product eluted in sodium phosphate, NaCl pH 7.4 with 200 mM imidazole.
The pTB NBSE was constructed from pTB 375 NBPE as follows:
pTB375
The background vector used for generation of pTB 375 was pZEN0042 (see UK patent 2253852) and contained the tetA/tetR inducble tetracycline resistance sequence from plasmid RP4 and the cer stability sequence from plasmid pKS492 in a pAT153 derived background. pTB375 was generated by the addition of an expression cassette consisting of the T7 gene 10 promoter, multiple cloning site and T7 gene 10 termination sequence. In addition, a terminator sequence designed to reduce transcriptional readthrough from the background vector was included upstream of the expression cassette.
pTB 375 NBPE
The unique EcoRI restriction site present in pTB 375 was removed. A new multiple cloning site containing the recognition sequences for the restriction enzymes NdeI, BamHI, PstI and EcoRI was introduced into pTB 375 between the NdeI and BamHI sites destroying the original BamHI site present in pTB 375.
pTB 375 NBSE
A new multiple cloning site containing the recognition sequences for the restriction enzvmes NdeI, BamHI, SmaI and EcoRI was introduced into pTB 375 NBPE between the NdeI and EcoRI sites. The oligonucleotide containing these restriction sites also contained 6 histidine codons located between the NdeI and BamHI sites in the same reading frame as the inititiator codon (ATG) present within the Ndel site.
By analogy to the above, assays designed to assess inhibition of CDK2 and CDK6 may be constructed. CDK2 (EMBL Accession No. X62071) may be used together with Cyclin A or Cvclin E (see EMBL Accession No. M73812), and further details for such assays are contained in PCT International Publication No. WO99/21845, the relevant Biochemical and Biological Evaluation sections of which are hereby incorporated by reference.
If using CDK-2 with Cyclin E partial co-purification may be achieved as follows:
Sf21 cells are resuspended in lysis buffer (50 mM Tris pH 8.2, 10 mM MgCl2, 1 mM DTT, 10 mM glycerophosphate, 0.1 mM sodium orthovanadate, 0.1 mM NaF, 1 mM PMSF, 1 ug/ml leupeptin and 1 ug/ml aprotinin) and homogenised for 2 minutes in a 10 ml Dounce homgeniser. After centrifugation, the supernatant is loaded onto a Poros HQ/M 1.4/100 anion exchange column (PE Biosystems, Hertford, UK). CDK-2 and Cyclin E are coeluted at the beginning of a 0-1M NaCl gradient (run in lysis buffer minus protease inhibitors) over 20 column volumes. Co-elution is checked by western blot using both anti-CDK-2 and anti-Cyclin E antibodies (Santa Cruz Biotechnology, California, US).
Although the pharmacological properties of the compounds of the formula (I) vary with structural change, in general activity possessed by compounds of the formula (I) in the above assays may be demonstrated at IC50 concentrations or doses in the range 250 xcexcM to 1 nM.
When tested in the above in-vitro assay the CDK4 inhibitory activity of Example 1 was measured as IC50=0.11 xcexcM and that of Example 2 as IC50=0.07 xcexcM.
The in-vivo activity of the compounds of the present invention may be assessed by standard techniques, for example by measuring inhibition of cell growth and assessing cytotoxicity.
Inhibition of cell growth may be measured by staining cells with Sulforhodamine B (SRB), a fluorescent dye that stains proteins and therefore gives an estimation of amount of protein (i.e. cells) in a well (see Boyd, M. R.(1989) Status of the NCI preclinical antitumour drug discovery screen. Prin. Prac Oncol 10:1-12). Thus, the following details are provided of measuring inhibition of cell growth:
Cells were plated in appropriate medium in a volume of 100 xcexcl in 96 well plates; media was Dulbecco""s Modified Eagle media for MCF-7, SK-UT-1B and SK-UT-1. The cells were allowed to attach ovemight, then inhibitor compounds were added at various concentrations in a maximum concentration of 1% DNISO (v/v). A control plate was assayed to give a value for cells before dosing. Cells were incubated at 37xc2x0 C., (5% CO2) for three days.
At the end of three days TCA was added to the plates to a final concentration of 16% (v/v). Plates were then incubated at 4xc2x0 C. for 1 hour, the supernatant removed and the plates washed in tap water. After drying, 100 xcexcl SRB dye (0.4% SRB in 1% acetic acid) was added for 30 minutes at 37xc2x0 C. Excess SRB was removed and the plates washed in 1% acetic acid. The SRB bound to protein was solubilised in 10 mM Tris pH7.5 and shaken for 30 minutes at room temperature. The ODs were read at 540 nm, and the concentration of inhibitor causing 50% inhibition of growth was determined from a semi-log plot of inhibitor concentration versus absorbance. The concentration of compound that reduced the optical density to below that obtained when the cells were plated at the start of the experiment gave the value for toxicity.
Typical IC50 values for compounds of the invention when tested in the SRB assay are in the range 1 mM to 1 nM.
According to a further aspect of the invention there is provided a pharmaceutical composition which comprises a pyrimidine derivative of the formula (I), or a pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof, as defined hereinbefore in association with a pharmaceutically-acceptable diluent or carrier.
The composition may be in a form suitable for oral administration, for example as a tablet or capsule, for parenteral injection (including intraveous, subcutaneous, intramuscular, intravascular or infusion) as a sterile solution, suspension or emulsion, for topical administration as an ointment or cream or for rectal administration as a suppository.
In general the above compositions may be prepared in a conventional manner using conventional excipients.
The pyrimidine will normally be administered to a warm-blooded animal at a unit dose within the range 5-5000 mg per square meter body area of the animal, i.e. approximately 0.1-100 mg/kg, and this normally provides a therapeutically-effective dose. A unit dose form such as a tablet or capsule will usually contain, for example 1-250 mg of active ingredient. Preferably a daily dose in the range of 1-50 mg/kg is employed. However the daily dose will necessarily be varied depending upon the host treated, the particular route of administration, and the severity of the illness being treated. Accordingly the optimum dosage may be determined by the practitioner who is treating any particular patient.
According to a mother aspect of the present invention there is provided a pyrimidine derivative of the formula (I), or a pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof, as defined hereinbefore for use in a method of treatment of the human or animal body by therapy.
We have found that the pyrimidine derivatives defined in the present invention, or a pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof, are effective cell cycle inhibitors (anti-cell proliferation agents), which property (without being bound by theory) is believed to arise from their (G1-S phase) CDK inhibitory properties. Accordingly the compounds of the present invention are expected to be useful in the treatment of diseases or medical conditions mediated alone or in part by CDK enzymes, i.e. the compounds may be used to produce a CDK inhibitory effect in a warm-blooded animal in need of such treatment. Thus the compounds of the present invention provide a method for treating the proliferation of malignant cells characterised by inhibition of CDK enzymes, i.e. the compounds may be used to produce an anti-proliferative effect mediated alone or in part by the inhibition of CDKs. Such a pyrimidine derivative of the invention is expected to possess a wide range of anti-cancer properties as CDKs have been implicated in many common human cancers such as leukaemia and breast, lung, colon, rectal, stomach, prostate, bladder, pancreas and ovarian cancer. Thus it is expected that a pyrimidine derivative of the invention will possess anti-cancer activity against these cancers. It is in addition expected that a pyrimidine derivative of the present invention will possess activity against a range of leukaemias, lymphoid malignancies and solid tumours such as carcinomas and sarcomas in tissues such as the liver, kidney, prostate and pancreas. In particular such compounds of the invention are expected to slow advantageously the growth of primary and recurrent solid tumours of, for example, the colon, breast, prostate, lungs and skin. More particularly such compounds of the invention, or a pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof, are expected to inhibit the growth of those primary and recurrent solid tumours which are associated with CDKs, especially those tumours which are significantly dependent on CDK for their growth and spread, including for example, certain tumours of the colon, breast, prostate lung, vulva and skin.
It is further expected that a pyrimidine derivative of the present invention will possess activity against other cell-proliferation diseases in a wide range of other disease states including leukemias, fibroproliferative and differentiative disorders, psoriasis, rheumatoid arthritis, Kaposi""s sarcoma, haemangioma, acute and chronic nephropathies, atheroma, atherosclerosis, arterial restenosis, autoimmune diseases, acute and chronic inflammation, bone diseases and ocular diseases with retinal vessel proliferation.
Thus according to this aspect of the invention there is provided a pyrimidine derivative of the formula (I), or a pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof, as defined hereinbefore for use as a medicament; and the use of a pyrimidine derivative of the formula (I), or a pharmaceutically-acceptable salt or in-vivo hydrolysable ester thereof, as defined hereinbefore in the manufacture of a medicament for use in the production of an anti-cancer, cell cycle inhibitory (anti-cell-proliferation) effect in a warm-blooded animal such as man. Particularly, a cell cycle inhibitory effect is produced at the G1-S phase by inhibition of CDK2, CDK4 and/or CDK6, especially CDK4 and CDK6.
According to a further feature of this aspect of the invention there is provided a method for producing an anti-cancer, cell cycle inhibitory (anti-cell-proliferation) effect in a warm-blooded animal, such as man, in need of such treatment which comprises administering to said animal an effective amount of a pyrimidine derivative as defined immediately above. Particularly, an inhibitory effect is produced at the G1-S phase by inhibition of CDK2, CDK4 and/or CDK6, especially CDK4 and CDK6.
As stated above the size of the dose required for the therapeutic or prophylactic treatment of a particular cell-proliferation disease will necessarily be varied depending on the host treated, the route of administration and the severity of the illness being treated. A unit dose in the range, for example, 1-100 mg/kg, preferably 1-50 mg/kg is envisaged.
The CDK inhibitory activity defined hereinbefore may be applied as a sole therapy or may involve, in addition to a compound of the invention, one or more other substances and/or treatments. Such conjoint treatment may be achieved by way of the simultaneous, sequential or separate administration of the individual components of the treatment. In the field of medical oncology it is normal practice to use a combination of different forms of treatment to treat each patient with cancer. In medical oncology the other component(s) of such conjoint treatment in addition to the cell cycle inhibitory treatment defined hereinbefore may be: surgery, radiotherapy or chemotherapy. Such chemotherapy may cover three main categories of therapeutic agent:
(i) other cell cycle inhibitory agents that work by the same or different mechanisms from those defined hereinbefore;
(ii) cytostatic agents such as antioestrogens (for example tamoxifen,toremifene, raloxifene, droloxifene, lodoxyfene), progestogens (for example megestrol acetate), aromatase inhibitors (for example anastrozole, letrazole, vorazole, exemestane), antiprogestogens, antiandrogens (for example flutamide, nilutamide, bicalutarnide, cyproterone acetate), LHRH agonists and antagonists (for example aoserelin acetate, luprolide), inhibitors of testosterone 5xcex1-dihydroreductase (for example finasteride), anti-invasion agents (for example metalloproteinase inhibitors like marimastat and inhibitors of urokinase plasminogen activator receptor function) and inhibitors of growth factor function, (such growth factors include for example platelet derived growth factor and hepatocyte growth factor such inhibitors include growth factor antibodies, growth factor receptor antibodies, tyrosine kinase inhibitors and serine/threonine kinase inhibitors); and
(iii) antiproliferative/antineoplastic drugs and combinations thereof, as used in medical oncology, such as antimetabolites (for example antifolates like methotrexate, fluoropyrimidines like 5-fluorouracil, purine and adenosine analogues, cytosine arabinoside); antitumour antibiotics (for example anthracyclines like doxorubicin, daunomycin, epirubicin and idarubicin, mitomycin-C, dactinomycin, mithramycin); platinum derivatives (for example cisplatin, carboplatin); alkylating agents (for example nitrogen mustard, melphalan, chlorambucil, busulphan, cyclophosphamide, ifosfamide, nitrosoureas, thiotepa); antimitotic agents (for example vinca alkaloids like vincrisitine and taxoids like taxol, taxotere); topoisomerase inhibitors (for example epipodophyllotoxins like etoposide and teniposide, amsacrine, topotecan). According to this aspect of the invention there is provided a pharmaceutical product comprising a pyrimidine derivative of the formula (I) as defined hereinbefore and an additional anti-tumour substance as defined hereinbefore for the conjoint treatment of cancer. An anti-emetic may also be usefully administered, for example when using such conjoint treatment as described above.
In addition to their use in therapeutic medicine, the compounds of formula (I) and their pharmaceutically acceptable salts are also useful as pharmacological tools in the development and standardisation of in vitro and in vivo rest svstems for the evaluation of the effects of inhibitors of cell cycle activity in laboratory animals such as cats, dogs, rabbits, monkeys, rats and mice, as part of the search for new therapeutic agents.
In the above other, pharmaceutical composition, process, method, use and medicament manufacture features, the alternative and preferred embodiments of the compounds of the invention described herein also apply.